1. Field of the Invention
The present invention relates to the field of display technology, and in particular to an array substrate and a manufacturing method thereof.
2. The Related Arts
Liquid crystal displays (LCDs) have a variety of advantages, such as thin device body, low power consumption, and being free of radiation, and are thus widely used in for example liquid crystal televisions, mobile phones, personal digital assistants (PDAs), digital cameras, computer monitors, and notebook computer screens. The liquid crystal display generally comprises an enclosure, a liquid crystal display panel arranged in the enclosure, and a backlight module mounted in the enclosure. The structure of the liquid crystal display panel is generally made up of a thin-film transistor (TFT) array substrate, a color filter (CF) substrate, and a liquid crystal layer between the two substrates and the operation principle is that a drive voltage is applied to the two glass substrates to control liquid crystal molecules of the liquid crystal layer to rotate in order to refract out light from a backlight module to generate an image.
Quantum dots are nanometer semiconductor crystals having a radius smaller than or close to Bohr radius and most are three-dimensional nanometer materials composed of elements of II-VI group or III-V group. Due to the quantum confinement effect, the transportation of electrons and holes in the quantum dots is constrained so as to change the continuous energy band into discrete energy levels. When the size of the quantum dot differs, the quantum confinement effect exhibits on electrons and holes is different, making the structure of discrete energy levels different. When excited by an external energy, quantum dots of different sizes give off light of different wavelengths, namely different colors of light. The advantages of quantum dot are that by adjusting the size of the quantum dot, it is possible to provide a range of wavelength of light emission that covers the infrared light and the entire visible light band and the waveband of the emission light is narrow with high degree of color saturation. The quantum dot material shows a high quantum conversion efficiency and the property of the material is stable. The manufacturing process and simple and diverse, allowing manufacturing thereof from solutions, of which the resources are rich. The quantum dot may absorb blue light that has a relatively short wavelength and, after being excited, exhibits a light color of a relatively long waveband. Such characteristics make the quantum dot capable of changing the color the light emitting from a backlight source.
A conventional liquid crystal display panel relies on color filtering achieved with an arrangement of color filter layers, such as a red filter layer, a green filter layer, and a blue filter layer, therein in order to convert white light emitting from a light source into monochromic light, such as red, green, and blue. The color filter layers of different colors allow light of different wavebands to pass so as to achieve colorful displaying of a liquid crystal display panel. With the advance of science and technology, people desire continuous improvement of color saturation and gamut for the liquid crystal display panel. To expand the color gamut range of a liquid crystal display panel requires increasing the color purity of the color filter layers and this in turn requires the content of pigment to be increased. This, however, lowers down light transmission rate of the color filter layer. Further, to maintain the display brightness of the liquid crystal display panel, it also needs to increase the intensity of emission light of the light source and this would lead to increased power consumption of the liquid crystal display panel.
The quantum dot technology brings total upgrading in all sectors, such as color gamut coverage, preciseness of color control, color purity of red, green, and blue colors and realizes, in an evolutionary way, full color displaying, providing the most realistic way of restoration of genuine color of an image, and is thus considered the world-wide high spot of display techniques and affecting the global revolution of display technology. The conventional quantum dot display technology is achieved by directly introducing quantum dots into between two substrates (a liquid crystal cell) of a liquid crystal display panel in order to supplement the insufficiency of color displaying with the color filter layers and to expand the range of displayed color gamut. However, the conventional manufacturing operations of the liquid crystal display panels constrain the exploitation of quantum dot performance. It is a issue to be studies for further improving the stability of quantum dots.